Olefin copolymer and preparation method and application thereof

The invention relates to the field of polymers, and particularly discloses an olefin copolymer and a preparation method and application thereof. The preparation method of the olefin copolymer comprises the steps that 1, in an inert gas environment, a tin-containing organic dilithium initiator, a conjugated diene monomer and a mono vinyl arene monomer are subjected to a first polymerization reaction in an inert solvent; 2, when the total monomer conversion rate of the conjugated diene monomer and the mono vinyl arene monomer reaches 70%-85%, a first polymerization reaction product and an isoprene monomer are subjected to a second polymerization reaction. According to preparation method, a tin-containing organic dilithium compound is used as the initiator, preparation is conducted in the mode of adding the raw materials step by step, and rubber prepared through the method has low rolling resistance and has a wide application prospect in the tire industry.